The present invention relates to a branch connector for connection between a main flexible pipe and at least one secondary flexible pipe, particularly for motor-vehicle cooling systems.
More specifically, the present invention relates to a branch connector of the type comprising a rigid, tubular insert with a first end, a second end and at least one third end, onto which the ends of a first branch of the main pipe, of a second branch of the main pipe and of at least one secondary pipe are fitted respectively, and a covering of plastics material which encloses the ends of the rigid insert and the ends of the main pipe and of the secondary pipe.
A known connector of the type indicated above is described in European patent application No. EP-A-243216. According to this document, the outer covering of the connector is injection-moulded onto the rigid insert after the ends of the first and second branches of the main pipe and of the secondary pipe have been fitted onto its ends. The material used for the covering must shrink by at least 1% as it cools after moulding so that, by virtue of its contraction, it exerts pressure on the ends of the main and secondary pipes and on the ends of the connector to create seals which are liquid-tight in use.
It is therefore necessary for the covering to be fairly thick and to extend axially for a certain distance at the ends of the connector which are covered by the ends of the main and secondary pipes in order to exert sufficient gripping force. This increases the costs of the material used and the time necessary to effect the moulding. Moreover, any defects or imperfections which may arise during the moulding of the covering seriously compromise its performance. Furthermore, the selection of the materials to be used for the covering is restricted to those which have high coefficients of shrinkage after moulding.